Molecular cloning, construction, and sequencing of an Ad4 shuttle plasmid containing an Ad4 HIV envelope gene, have been completed. The plasmid is ready for the next phase of producing the recombinant virus. Construction of an Ad4 shuttle plasmid containing the HIV gag gene is on-going. Exploration of the optimal method for generation and production of the Ad4-HIV recombinants on a human diploid cell line are underway. A new Ad4 luciferase construct for use in Ad4 seroprevalence studies is being developed. Ad recombinants containing the green fluorescent protein (GFP) have been generated. These will prove valuable in tracing where the replicating Ad recombinants traffic following administration and how long they persist in the body.